1. Field of the Invention
This invention relates to a multi-piece solid golf ball having a structure of at least four layers which is improved in flying performance, hitting feel, controllability and durability.
2. Prior Art
Golf balls of the thread wound balata structure have been long favored by many professional golfers and skilled golfers. Wound golf balls are superior in feeling and controllability which are essential factors for skilled golfers. Because of their structure that is receptive to more spin, however, wound golf balls are less controllable in flying distance under certain conditions. For example, when the ball is hit against the wind, it tends to fly sharply high, failing to travel a satisfactory carry. When the ball is hit into fair winds, it will travel a greater distance than intended.
Recently, modern two-piece solid golf balls designed for adequate spin are considered acceptable by some skilled golfers. The absolute difference from the wound golf balls still resides in spin receptivity since the two-piece solid golf balls are characterized by a lower spin rate. As compared with the wound golf balls, the two-piece solid golf balls are superior with respect to the carry and improved in straight flight due to a low spin rate, but upon long iron shots requiring controllability, they tend to fly too much, indicating a loss of control. With respect to feel, the two-piece solid golf balls are approaching to the wound golf balls with room for improvement still left.
Therefore, a primary object of the present invention is to provide a multi-piece solid golf ball which will travel a satisfactory carry as inherent to solid golf balls when shot with a driver, receives more spin when shot with an iron, and has controllability closer to the wound balata golf ball.
The present invention provides a multi-piece solid golf ball having a structure of at least four layers, comprising a core having a structure consisting of at least two layers and a cover enclosing the core and consisting of inner and outer cover layers. The outer cover layer has a hardness of 40 to 60 degrees on Shore D. The inner cover layer has a hardness of up to 53 degrees on Shore D and lower than that of the outer cover layer.